Field of the Invention
The present invention generally relates to the field of surgical sutures, and more specifically relates to surgical sutures having barbs.
Description of the Related Art
Surgical sutures are used to close wounds and surgical incisions, and to repair damaged or severed muscles, vessels, and tissue. Typically, the suture is attached at one end to a needle, and the needle is drawn through tissue to form one or more loops holding the tissue together. The suture is subsequently tied off using one or more knots so that the tissue will remain drawn together.
The approximation of subcutaneous and dermal tissue layers are directly related to the final cosmetic outcome of an incision. Ideally, the tissue edges are aligned and apposed under minimal tension, which directly contributes to the degree of scar formation and the appearance of the closure.
Although conventional surgical sutures are very effective and reliable for closing wounds, additional sutures have been developed for use during certain types of medical procedures. One new type of suture, barbed sutures, have projecting barbs that allow the suture to be used to close wounds, approximate tissue, tighten tissue, and attach prosthetic devices—all without using knots. Barbed sutures achieve proper tensioning and fixation by applying tension to the suture. For example, U.S. Pat. No. 5,931,855 discloses barbed sutures that are used for cosmetic procedures such as brow-lifts and face-lifts.
Barbed sutures lend themselves to closure of subcutaneous and dermal tissue layers by providing speed and ease of use, no knot-related complications, even distribution of tension along or across the incision, and adequate wound holding strength to keep the tissue edges aligned throughout the critical wound healing period.
Existing barbed sutures allow for the passage of a barbed suture through tissue in a first direction to minimize drag, while maximizing holding strength in an opposite, second direction. These existing barbed sutures are not designed to be locally reversible without causing tissue trauma and plastic deformation and damage to the barbs themselves rendering them unable to adequately approximate tissue. Additionally, existing barbed suture designs are prone to damage because the barbs are cut into a monofilament suture, which essentially forms a hinge holding the barb to the monofilament. If a barbed suture “bite” is misplaced intra-operatively, a surgeon's only recourse is to cut the misplaced suture and continue the stitch pattern with a new barbed suture.
In spite of the above advances, there remains a need for barbed sutures that are locally reversible, that allow for passage of the barbed suture through tissue in two directions without causing trauma to the tissue or damaging the barbs, and that provide adequate tissue holding strength suitable to approximate tissue.